About me

I am a PhD student at Max-Planck-Institut for Astrophysics working with Prof. Eiichiro Komatsu. I am interested in line intensity mapping, specifically with the Lyman-α emission line. On the observational side, I stacked the Lyman-α intensity around detected galaxies in the HETDEX survey and found extended emission, so-called Lyman-α halos, out to more than 100 kpc. Now I am working on measuring the galaxy-Lyman-α intensity cross-power spectrum with a larger galaxy sample and spectra from HETDEX out to larger scales.

I have also developed the SIMPLE code, which stands for Simple Intensity Map Producer for Line Emission. It can quickly generate intensity maps based on lognormal galaxy simulations in redshift space and simulate observational effects such as limited resolution, masks, and galaxy selection functions.


My publication list can also be found on Inspire, ADS, and arXiv .

As first author

  • “SIMPLE: Simple Intensity Map Producer for Line Emission” – M. Lujan Niemeyer, J. L. Bernal, E. Komatsu; ApJ 958 4; arXiv:2307.08475
  • “Lyα Halos around [O III]-selected Galaxies in HETDEX” – M. Lujan Niemeyer, W. P. Bowman, R. Ciardullo et al.; ApJL 934 L26; arXiv:2207.11098
  • “Surface Brightness Profile of Lyman-α Halos out to 320 kpc in HETDEX” – M. Lujan Niemeyer, E. Komatsu, C. Byrohl et al.; ApJ 929 90; arXiv:2203.04826
  • As contributing author

  • “Absorption Troughs of Lyman Alpha Emitters in HETDEX” – L. H. Weiss, D. Davis, K. Gebhardt et al.; ApJ 962 102; arXiv:2401.02490
  • “HETDEX Public Source Catalog 1—Stacking 50,000 Lyman Alpha Emitters” – D. Davis, K. Gebhardt, E. Mentuch Cooper et al.; ApJ 954 209; arXiv:2307.03096
  • “HETDEX Public Source Catalog 1: 220 K Sources Including Over 50 K Lyα Emitters from an Untargeted Wide-area Spectroscopic Survey” – E. Mentuch Cooper, K. Gebhardt, D. Davis et al.; ApJ 943 177; arXiv:2301.01826
  • “The Active Galactic Nuclei in the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX). II. Luminosity Function” – C. Liu, K. Gebhardt, E. Mentuch Cooper et al.; ApJ 935 132; arXiv:2207.11801
  • “The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections” – K. Gebhardt, E. Mentuch Cooper, R. Ciardullo et al.; ApJ 923 217; arXiv:2110.04298
  • “Detection of Lyman Continuum from 3.0 < z < 3.5 Galaxies in the HETDEX Survey” – D. Davis, K. Gebhardt, E. Mentuch Cooper et al.; ApJ 920 122; arXiv:2107.11319
  • Outreach

    I lead several planetarium shows for students to learn about the research at MPA. I also helped organize the Girl's Day at MPA, where high school students can try out currently male-dominated jobs and learn about astrophysics and cosmology at MPA.

    I wrote a public science article about my early PhD work on Lyα halos. You can find them here:
    English: Galaxies light up hydrogen halos around neighbouring galaxies;
    Deutsch: Galaxien beleuchten Wasserstoff-Halos benachbarter Galaxien.

    Get in touch

    • Email

    • Address

      Max-Planck-Institut für Astrophysik
      Karl-Schwarzschild-Str. 1
      85748 Garching